Systems, methods and computer program products for averaging learned levels in the presence of digital impairments based on patterns

• US 6,754,258 B1
• Filed: 10/29/1999
• Issued: 06/22/2004
• Est. Priority Date: 10/29/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ye, Hua, Ware, Malcolm Scott, Davis, Gordon Taylor, Hwang, Dongming, Abdelilah, Youssef
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Ha, Dac V.
• Application Number:
  US09/431,564
• Time in Patent Office: 1,698 Days
• Field of Search: 375/220, 375/222, 375/242, 375/243, 375/254, 375/257, 375/285, 375/296, 375/340, 375/346, 455/63, 455/67.1, 455/67.3, 455/296, 370/201, 370/252, 370/342, 370/509
• US Class Current: 375/220
• CPC Class Codes: H04B 14/048 Non linear compression or expansion

Abstract

Methods, systems and computer program products for averaging measured levels from differing frame intervals based on a digital impairment pattern associated with the frame intervals are provided. Measured levels from frame intervals with the same digital impairment pattern may be averaged together and the measured levels replaced with the average. By averaging frame intervals based on a digital impairment pattern, the present invention may reduce the impact of noise by increasing the signal to noise ratio of the levels utilized for constellation generation. The use of the digital impairment patterns for determining which frame intervals to average may reduce the likelihood that digital impairments will corrupt the average by, for example, collapsing measured levels from one code point onto another code point. If the frame intervals have the same digital impairment pattern then it is likely that the differences in the values of the in the measured levels of the frame intervals are the result of random noise rather than digital impairments and, therefore, may be averaged together to reduce the impact of the random noise.

Claims

1. A method of averaging measured levels of code point sequences from a plurality of frame intervals in the presence of digital impairments, the method comprising the steps of:

determining respective patterns associated with each of the plurality of frame intervals;

averaging measured levels from frame intervals of the plurality of frame intervals having the same pattern; and

replacing the measured levels for the averaged intervals with the average levels.

2. A method according to claim 1, wherein the step of determining respective patterns comprises the step of determining digital impairments associated with each of the frame intervals so as to provide a pattern of digital impairments for each frame interval.

3. A method according to claim 2, wherein the pattern of digital impairments comprise a pattern of robbed-bit signaling and digital PADs (Packet Assembler/Disassemblers).

4. A method according to claim 1, wherein the step of determining respective patterns comprise the step of determining a pattern of clusters and/or skips for each of the frame intervals.

5. A method according to claim 1, wherein the step of determining respective patterns comprises the step of obtaining an array of values wherein the values in the array indicate a number of frame intervals having a common pattern and the frame intervals having the common pattern.

6. A method according to claim 5, wherein the step of averaging measured levels comprises the steps of;

accessing the array of values to obtain a value of a number of frame intervals having a common pattern;

accessing the array of values to obtain a frame interval identification of the frame intervals having the common pattern;

determining a running sum corresponding to each measured level for the frame interval corresponding to the frame interval identifications;

repeating the steps of accessing the array of values to obtain frame interval identifications and determining the running sum until a number of frame interval identifications has been obtained which corresponds to the value of the number of frame intervals having a common pattern; and

determining an average value for each running sum by dividing the running sum for each measured level by the value of the number of frame intervals having a common pattern if the number of frame interval identifications has been obtained which corresponds to the value of the number of frame intervals having a common pattern.

7. A method according to claim 6, wherein the step of replacing the measured levels comprises the steps of replacing the measured levels in the frame intervals corresponding to the frame interval identifications with the corresponding average value.

8. A system for averaging measured levels of code point sequences from a plurality of frame intervals in the presence of digital impairments, comprising:

means for determining respective patterns associated with each of the plurality of frame intervals;

means for averaging measured levels from frame intervals of the plurality of frame intervals having the same pattern; and

means for replacing the measured levels for the averaged intervals with the average levels.

9. A system according to claim 8, herein the means for determining respective patterns comprises means for determining digital impairments associated with each of the frame intervals so as to provide a pattern of digital impairments for each frame interval.

10. A system according to claim 9, wherein the pattern of digital impairments comprise a pattern of robbed-bit signaling and digital PADs (Packet Assembler/Disassemblers).

11. A system according to claim 8, wherein the means for determining respective patterns comprise means for determining a pattern of clusters and/or skips for each of the frame intervals.

12. A system according to claim 8, wherein the means for determining respective patterns comprises means for obtaining an array of values, wherein the values in the array indicate a number of frame intervals having a common pattern and the frame intervals having the common pattern.

13. A system according to claim 12, wherein the means for averaging measured levels comprises:

means for accessing the array of values to obtain a value of a number of frame intervals having a common pattern;

means for accessing the array of values to obtain a frame interval identification of the frame intervals having the common pattern;

means for determining a running sum corresponding to each measured level for the frame interval corresponding to the frame interval identifications;

means for repeating accessing the array of values to obtain frame interval identifications and determining the running sum until a number of frame interval identifications has been obtained which corresponds to the value of the number of frame intervals having a common pattern; and

means for determining an average value for each running sum by dividing the running sum for each measured level by the value of the number of frame intervals having a common pattern if the number of frame interval identifications has been obtained which corresponds to the value of the number of frame intervals having a common pattern.

14. A system according to claim 13, wherein the means for replacing the measured levels comprises means for replacing the measured levels in the frame intervals corresponding to the frame interval identifications with the corresponding average value.

15. A computer program product for averaging measured levels of code point sequences from a plurality of frame intervals in the presence of digital impairments, comprising:

a computer-readable storage medium having computer readable program code embodied in said medium, said computer-readable program code comprising;

computer-readable program code for determining respective patterns associated with each of the plurality of frame intervals;

computer-readable program code for averaging measured levels from frame intervals of the plurality of frame intervals having the same pattern; and

computer-readable program code for replacing the measured levels for the averaged intervals with the average levels.

16. A computer program product according to claim 15, wherein the computer-readable program code for determining respective patterns comprises computer-readable program code for determining digital impairments associated with each of the frame intervals so as to provide a pattern of digital impairments for each frame interval.

17. A computer program product according to claim 16, wherein the pattern of digital impairments comprise a pattern of robbed-bit signaling and digital PADs (Packet Assembler/Disassemblers).

18. A computer program product according to claim 15, wherein the computer-readable program code for determining respective patterns comprise computer-readable program code for determining a pattern of clusters and/or skips for each of the frame intervals.

19. A computer program product according to claim 15, wherein the computer readable program code for determining respective patterns comprises computer readable program code for obtaining an array of values, wherein the values in the array indicate a number of frame intervals having a common pattern and the frame intervals having the common pattern.

20. A computer program product according to claim 19, wherein the computer readable program code for averaging measured levels comprises:

computer readable program code for accessing the array of values to obtain a value of a number of frame intervals having a common pattern;

computer readable program code for accessing the array of values to obtain a frame interval identification of the frame intervals having the common pattern;

computer readable program code for determining a running sum corresponding to each measured level for the frame interval corresponding to the frame interval identifications;

computer readable program code for repeating accessing the array of values to obtain frame interval identifications and determining the running sum until a number of frame interval identifications has been obtained which corresponds to the value of the number of frame intervals having a common pattern; and

computer readable program code for determining an average value for each running sum by dividing the running sum for each measured level by the value of the number of frame intervals having a common pattern if the number of frame interval identifications has been obtained which corresponds to the value of the number of frame intervals having a common pattern.

21. A computer program product according to claim 20, wherein the computer readable program code for replacing the measured levels comprises computer readable program code for replacing the measured levels in the frame intervals corresponding to the frame interval identifications with the corresponding average value.